SUMMARY 
The reduction division was studied and the number of chromosomes 
determined of the following Triticum species: 
— 
O © © N 9 UN 8 & D — 
er lo lame dor À op iz) 
12: 
13: 
14. 
15: 
16. 
172 
Haploid 
Number 
.monococcum L. var. flavescens Kcke. (fig. 31) 7 
. dicoccum Schrk. var. rufum Kcke. (fig. 32 and 33). . 14 
.turgidum L. var. megalopolitanum Kcke (fig. 42). . 14 
. durum Desf. var. leucurum Al. (fig. 35). . 14 
. polonicum L. var. levissimum Hall (fig. 36 and 37) . . 14 
. vulgare Vill. var. lutescens Al. (fig. 34) . . 21 
x , +, ferrigmenm Al 2] 
bs ee „ ervihrospennum Keke 2a 21 
5 » „ multuram Al RO 
Er , » alborubrum Kcke. Geldersche risweit (fig. 
13) a on 
ie » » albidum Al. Wilhelmina (fig. 38 and 43). 21 
5, ee 3 Salmperiaallla Zi 
© PTT % „ Millioen II 24 
. compactum Host var. splendens Al . 21 
> MONET Maza: 21 
. Spelta L. var. Duhamelianum Mazz. 21 
. dicoccoides Kcke. var. Aaronsohnii 7 
The pollen-mother-cells in the young anthers lie close together (fig. 
54) ; in the later stages they form a ring, when seen in transverse sections. 
The first division stage is a contraction of the chromatic substance in 
the nucleus (fig. 1). This is followed by the leptonema-stage, synapsis 
(a second contraction) (fig. 50), zygonema (fig. 4), a third contraction 
stage (known as , second contraction”’ fig. 2), strepsinema (fig. 5 and 6) 
and diakinesis (fig. 3). After diakinesis a fourth contraction was obser- 
